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Scientists have found the secret behind a property of solid materials known as ferroelectrics, showing that quasiparticles moving in wave-like patterns among vibrating atoms carry enough heat to turn the material into a thermal switch when an electrical field is applied externally.

A key finding of the study is that this control of thermal conductivity is attributable to the structure of the material rather than any random collisions among atoms. Specifically, the researchers describe quasiparticles called ferrons whose polarization changes as they “wiggle” in between vibrating atoms – and it’s that ordered wiggling and polarization, receptive to the externally applied electrical field, that dictates the material’s ability to transfer the heat at a different rate.

“We figured out that this change in position of these atoms, and the change of the nature of the vibrations, must carry heat, and therefore the external field which changes this vibration must affect the thermal conductivity,” said senior author Joseph Heremans, professor of mechanical and aerospace engineering, materials science and engineering, and physics at The Ohio State University.  “People tend to think atom vibrations are a given fact and don’t respond to an electric field or a magnetic field. And we are saying you can affect them with an electric field.”

With the use of a simple external electrical stimulus, the thermal conductivity in this type of material can be changed at room temperature rather than at the extremely low temperatures required to control most candidate materials for solid-state heat switches, enhancing the possibilities for real-world applications of the technology, the researchers say.

The material used in the study is a common lead zirconium titanate ceramic belonging to a class of materials called piezoelectrics, which change shape when an electric field is applied to them or produce an electrical charge under mechanical stress.

Ferroelectrics, a subset of piezoelectrics, are materials in which the electrical charges on the atoms can spontaneously form electrical dipoles that all align in the same direction, forming what is known as polarization. These dipoles can be switched by an external electric field.

“The quasiparticle has always been there. It just hasn’t been identified and measured,” said first author Brandi Wooten, a PhD student in materials science and engineering at Ohio State.

Wooten likened ferrons’ behavior to a stadium wave, with each sports fan representing a cell of atoms collected together in a crystal.

This heat-transferring property is induced by the electric field through a phenomenon known as the piezoelectric strain: The lattice contracts or stretches when the voltage is applied, with atoms and forces between them moving back and forth, ultimately changing the mechanical properties of the material and, as a result, changing its thermal conductivity, said Heremans, also an Ohio Eminent Scholar in Nanotechnology.

“The ferron is also sensitive to strain in the solid. Since the ferron carries heat, that makes the amount of heat carried dependent on the electrical field,” he said. “So, we wrote a new theory that relates an external electric field, the strain it induces in a ferroelectric, and ultimately how this strain affects the thermal conductivity.”

The theory is predictive, so researchers can now use it to find materials where the effect is much larger, ultimately leading to materials where it is large enough to be used in heat switches in everyday applications, like collection of solar power.

The application of an electrical field to the material produced a 2 percent difference between maximum and minimum conductivity – as the new theory predicted would be the case. A series of experiments quantifying the atomic vibrations through measuring the velocity of the material’s sound waves and equilibrium and transport properties validated “that this all depends only on the material structure, not necessarily what’s scattering the vibrations,” Wooten said.

The researchers are now studying other materials that might increase that change in thermal conductivity by up to 15%, as the new theory predicts.

For more information: Science Advances

Plasmatreat GmbH, Germany, the world market leader for atmospheric plasma technology, is launching three new plasma nozzles that expand its large product portfolio to include applications for treating temperature-sensitive materials, the wide-area pretreating of surfaces, and homogeneous surface coating.

Plasma technology can be used to modify the surface properties of a wide variety of materials in order to optimally prepare materials and material combinations for subsequent processes. Plasmatreat has developed various processes for this purpose. In the fine cleaning of metals or glass, for example, with Openair-Plasma, surfaces are gently and safely freed from dust, grease, release agents and additives. This increases the surface energy and optimizes the wettability of the substrate surface.

During activation, the surface of the substrate, e.g. the non-polar plastic, reacts with molecules excited by plasma. In this process, oxygen groups are introduced into the top layer of the plastic, significantly improving adhesion. This makes bonding, painting, printing or gasketing easier, or, in some cases, possible in the first place.

For the environmentally friendly pretreatment, plasma is applied to the substrate with pinpoint accuracy using simple compressed air through a special nozzle.

One of Plasmatreat’s core competencies is the application-specific coordination of distance, treatment width and traversing speed – and the selection of the right nozzles for the process in question. Another process, PlasmaPlus technology, uses nanocoatings to create functionalized surfaces, such as an adhesion promoter layer or an anti-corrosion coating. In this technology, a precursor is added to the plasma jet and a nanolayer with the desired properties is then deposited.

With the RD2005PAD, a rotary nozzle for coating with PlasmaPlus technology is now available for the first time. This process uses nanocoatings to create specifically functionalized surfaces that are tailor-made to meet customer requirements with regard to planar materials. The spectrum ranges from superhydrophobic, adhesion-promoting to superhydrophilic coatings.

With the RD2005PAD, the first rotary nozzle with precursor feed, Plasmatreat is once again the pioneer. Until now, only static nozzles were used worldwide for this coating application, which had its focus in the selective modification of surfaces. The new nozzle, which rotates around a rotation axis, is now suitable for coating flat materials and now also offers the advantage of a particularly homogeneous treatment with high intensity in the PlasmaPlus process. This produces a reliable functional layer that enables optimum bonding, printing or painting of the coated surface.

Plasmatreat has developed another new nozzle, the PFW10LT, a low-temperature nozzle that also activates thermally sensitive materials and surfaces with high intensity. It is designed for use at low temperatures below 60 °C and performs a particularly gentle pretreatment of plastics prior to subsequent processes, e.g. bonding. The plasma nozzle is particularly suitable for small treatment areas and contours such as boreholes or groove areas, for low-lying applications in 3D components or for medical components and products. The PFW10LT plasma nozzle is used for a treatment width of approx. 4 mm.

Plasmatreat’s third new plasma nozzle, the PFW100, is now available to treat flat components or surfaces at high process speeds and at the same time over a large width. It is particularly suitable for the pretreatment of heat-sensitive materials such as thin plastic films or textile products such as synthetic nonwovens. It can also be used for the surface cleaning of glass or metal. The PFW100 performs uniform pretreatment over a width of 100 mm per plasma nozzle at relative speeds of up to 200 m/min. The treatment width can be flexibly varied via the modular arrangement of several nozzles.

In order to treat flat components or surfaces at high process speeds and at the same time over a large width, the PFW100 is now available as a suitable plasma nozzle.

 

Image – The RD2005PAD is a rotating nozzle for coating of planar materials.

 

For more information:

Plasmatreat GmbH

https://www.plasmatreat.com/

 

Each year, the United States spends almost a trillion dollars trying to combat metallic corrosion, an electrochemical reaction which occurs when metals oxidize and begin to rust. Now, a team of researchers led by the Ohio State University (OSU) has estimated how much corrosion is gradually worsening global carbon emissions.

Although earlier research has already estimated the economic cost of corrosion to be about three to four percent of United States’ gross domestic product, this is the first study to quantify the environmental impact associated with steel corrosion.

Global steel production has increased steadily for decades and, since steel has poor resistance to corrosion, part of that demand is to replace steel from construction materials that have become corroded over time. According to the experts, reducing the amount of steel which needs to be replaced due to corrosion could have significant effects on the amount of greenhouse gases produced to make steel.

“Given society’s reliance on coal fuel, iron and steel production is one of the largest greenhouse gases emitters of any industry. But most of the costs associated with the industry stem from the energy that goes into creating steel, and that energy is lost as the steel reverts to rust, which is like its original form of iron ore,” explained study senior author Gerald Frankel, a professor of Materials Science and Engineering at OSU.

By using historical carbon dioxide intensity data in order to estimate CO2 levels per year starting from 1960, the scientists found that, in 2021, steel production accounted for 27 percent of the carbon emissions of the global manufacturing sector, and approximately 10.5 percent of the total carbon emissions worldwide, while corroded steel emissions accounted for about 1.6 to 3.4 percent of emissions.

Fortunately, due to regulations placed on the steel industry, technological advancements in the steel industry have resulted in a 61 percent reduction in energy consumption over the past half a century. Nonetheless, policy makers and industry officials should still act urgently to amend and coordinate international policy concerning steel production and corrosion management.

“Coordinated international strategies, as well as decreasing global steel demand, by using best practices for corrosion mitigation, could better improve global corrosion management strategies and drastically reduce the rise in greenhouse gas emissions we’re seeing due to repeatedly replacing corroded steel,” Frankel said.

If such actions are not undertaken soon, greenhouse emissions caused by the steel industry could spike to 27.5 percent of the global carbon emissions by as early as 2030, with corroded steel representing four to nine percent of that number. This could have dire impacts on the Earth’s climate.

“Global warming is a societal challenge that takes coordination of a lot of multidisciplinary approaches. Our work is bringing to light an issue that seems to have gone under the radar in terms of the importance of adding to the problem,” Frankel concluded.

For more information: npj Materials Degradation

A Missouri S&T research team was recently awarded a $2 million grant from the United States Department of Energy to research technologies to improve the operating efficiency of electric arc furnaces (EAFs) used for steelmaking. 
 
“It takes a tremendous amount of power to run an EAF, and we are looking for new ways to lower that energy footprint,” says Dr. Ronald O’Malley, the F. Kenneth Iverson Endowed Chair of Steelmaking Technologies and director of the Kent D. Peaslee Steel Manufacturing Research Center at Missouri S&T. “We are working toward implementing a next-generation dynamic control system for the EAF so we can optimize EAF operating efficiency under changing input conditions using new sensor systems.” 
 
The project is titled “Intelligent Dynamic EAF Advisory System (IDEAS) for Improving EAF Operating Efficiency.” This $2 million grant is part of a larger three-phase project.  
 
For the first phase, the research team assessed the current systems in place at the two steel plants that are partners in the study and developed the conceptual framework for the future aspects of the project. 
 
This stage required significant data analysis for the process, integration of existing control modules already in place, implementation of new control modules and development and testing of new fiber optic sensing technologies in the lab for use in the EAF. 
 
In Phase 2, the new fiber optic sensing technologies will be implemented in the plants along with new control systems, directed energy input and EAF slag property models. 
 
“In basic terms, the fiber optic system will provide a whole new set of tools for EAF optimization,” O’Malley says. “We will be able to better examine the condition of the EAF and the impact of operating variables on the process in real time to provide feedback to the operator and improve energy efficiency, operating cost and yield.” 
 
The new sensor technology and control modules will be installed at the two partner steel plants, which are Big River Steel in Osceola, Arkansas, and Commercial Metals Company (CMC) in Birmingham, Alabama. 
 
After that, the systems will go live, and the data collection process will begin. Throughout the process, the plant employees will be trained on how to use the new technology. Then, in the final stage, the researchers will analyze the performance improvements in progress and determine what changes should be implemented to further improve the system. 
 
“Something people should also appreciate about this project is the benefits to the student researchers involved,” says O’Malley. “S&T and ASU will have a team of undergraduate and graduate students working on this project. You can’t beat the hands-on experience that this will provide for our students.” 
 

For more information: Missouri University of Science and Technology 

Photo: Dr. Ron O’Malley, a professor at Missouri S&T, is leading a study to improve the energy footprint associated with electric arc furnaces. Photo by Michael Pierce/Missouri S&T. 

A Missouri S&T research team was recently awarded a $2 million grant from the United States Department of Energy to research technologies to improve the operating efficiency of electric arc furnaces (EAFs) used for steelmaking. 
 
“It takes a tremendous amount of power to run an EAF, and we are looking for new ways to lower that energy footprint,” says Dr. Ronald O’Malley, the F. Kenneth Iverson Endowed Chair of Steelmaking Technologies and director of the Kent D. Peaslee Steel Manufacturing Research Center at Missouri S&T. “We are working toward implementing a next-generation dynamic control system for the EAF so we can optimize EAF operating efficiency under changing input conditions using new sensor systems.” 
 
The project is titled “Intelligent Dynamic EAF Advisory System (IDEAS) for Improving EAF Operating Efficiency.” This $2 million grant is part of a larger three-phase project.  
 
For the first phase, the research team assessed the current systems in place at the two steel plants that are partners in the study and developed the conceptual framework for the future aspects of the project. 
 
This stage required significant data analysis for the process, integration of existing control modules already in place, implementation of new control modules and development and testing of new fiber optic sensing technologies in the lab for use in the EAF. 
 
In Phase 2, the new fiber optic sensing technologies will be implemented in the plants along with new control systems, directed energy input and EAF slag property models. 
 
“In basic terms, the fiber optic system will provide a whole new set of tools for EAF optimization,” O’Malley says. “We will be able to better examine the condition of the EAF and the impact of operating variables on the process in real time to provide feedback to the operator and improve energy efficiency, operating cost and yield.” 
 
The new sensor technology and control modules will be installed at the two partner steel plants, which are Big River Steel in Osceola, Arkansas, and Commercial Metals Company (CMC) in Birmingham, Alabama. 
 
After that, the systems will go live, and the data collection process will begin. Throughout the process, the plant employees will be trained on how to use the new technology. Then, in the final stage, the researchers will analyze the performance improvements in progress and determine what changes should be implemented to further improve the system. 
 
“Something people should also appreciate about this project is the benefits to the student researchers involved,” says O’Malley. “S&T and ASU will have a team of undergraduate and graduate students working on this project. You can’t beat the hands-on experience that this will provide for our students.” 
 

For more information: Missouri University of Science and Technology 

Photo: Dr. Ron O’Malley, a professor at Missouri S&T, is leading a study to improve the energy footprint associated with electric arc furnaces. Photo by Michael Pierce/Missouri S&T. 

Across the world, some 80 million people suffer from glaucoma, a number that’s expected to swell to 111 million by 2040. Today, an estimated three million have been diagnosed in the United States.

But common as it may be, glaucoma is a formidable affliction. It takes root with an accumulation of fluid in the eyes, forming a bubble of extra pressure that slowly damages the optical nerve. At first touch, symptoms can be imperceptible—perhaps a bit of blurriness, or a slight weakening of your peripheral sight. Over time, the angle through which your pupils peer might narrow further and further—until one day, you might wake up with your field of vision completely zeroed out. No cure exists.

Glaucoma can be treated by lowering the extra pressure in the eyes, most often with prescription eye drops. Now, Pohang University of Science and Technology (POSTECH) in South Korea has engineered a way to make the treatment more futuristic, with a smart contact lens that automatically delivers doses of medication over time, straight onto the eyeballs.

The contact lens, developed by a team from POSTECH’s department of materials science and engineering, is fitted with hollow nanowires made of gold, which serve as sensors that constantly track intraocular pressure (IOP). POSTECH’s invention can also administer the appropriate treatment in response to the diagnostic data. It’s powered by an integrated circuit chip, which allows the lens to release amounts of a drug on demand.

Similarly to diabetes, glaucoma is a treatable disease that patients must manage for life. Also, like diabetes, the greatest uphill battle today is adherence. Many patients struggle to remember to check IOP levels, or simply find the monitoring too much of a hassle.

“We hope the early commercialization of the newly developed theranostic smart contact lens for diagnosing and treating glaucoma intraocular pressure [can] provide glaucoma patients’ compliance,” said Sei Kwang Hahn, a POSTECH professor and the study’s lead.

For more information: Nature Communications

 

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